The biggest smartphone market in the world just shrank for the first time in 6 years

Customers get their preordered iPhone 6 at an Apple store in Beijing. Thomson Reuters China's smartphone market has reached saturation, according to a new study by the industry analyst IDC that carries potentially significant implications for the global handset industry led by giants like Apple Inc. and Samsung Electronics Co. Ltd.

During the first quarter of 2015, smartphone shipments in the world's most populous country shrank for the first time in six years, to 98.8 million, down 4.3% from a year earlier, IDC said in report Monday, attributing the slump to "market saturation."

The rise of Chinese consumers has fueled booming demand for smartphones in recent years, lifting firms including Apple — which made a record $16.8 billion in revenue in China last quarter thanks to its iPhone 6 series launch — and Beijing-based Xiaomi, which grew into a $46 billion company in just four years.

China overtook the US in 2011 to become the world's largest smartphone market.

But IDC's data suggesting that a slowdown has already begun could pose questions for the industry.

Thanks to its large-screen iPhone 6, Apple consolidated its position in the shrinking Chinese market, claiming 14.7% market share, ahead of Xiaomi and Huawei at 13.7% and 11.4%, respectively, according to IDC.

Samsung, the global leader, came in fourth in China with a 9.7% share.

The slowdown in China will increase pressure on manufacturers to seek growth in India and Southeast Asia, where striking partnerships with distributors will prove critical, IDC analyst Xiaohan Tay said.

Xiaomi, for one, has actively courted both online and offline sellers in India over the past year. The company, which has sold its handsets on Flipkart.com for the past year, said last month it would also sell its phones at The Mobile Store retail chain throughout the country.